#include<fstream>
#include<iostream>
#include<vector>
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
int nrLit='z'-'a'+1;
struct node{
    int cnt;//cate cuvinte "trec"
    int finish;//cate cuvinte se termina pe pozitia crt
    vector<node*>lit;
    
    node(){
        cnt=0;
        finish=0;
        lit.resize(nrLit,nullptr);
    };
};

node* addWord(string &cuv,int poz,node *crt){    

   
    if(crt==nullptr){
        crt=new node();
    }
    crt->cnt++;
     if(poz==cuv.size()){
        crt->finish++;   
        return crt;
    }
    crt->lit[cuv[poz]-'a'] =addWord(cuv,poz+1,crt->lit[cuv[poz]-'a']);
    
    
    return crt;
}
int countWord(string &cuv,int poz,node *crt){
    
    if(crt==nullptr){
        return 0;
    }
    if(poz==cuv.size()){
        return crt->finish;
    }
    return countWord(cuv,poz+1,crt->lit[cuv[poz]-'a']);
}
void eraseWord(string &cuv,int poz,node *crt,bool &checkErase){//checkErase ne spune daca cuvantul cuv se afla in lista sau nu
    if(crt==nullptr){
        checkErase=false;
        return ;
    }
    if(poz==cuv.size()){
        checkErase=true;
        crt->finish--;
        crt->cnt--;
        return;
    }
    eraseWord(cuv,poz+1,crt->lit[cuv[poz]-'a'],checkErase);
    if(checkErase){//inseamna ca exista cuvantul in trie
        crt->cnt--;
    }
}
int countPrefix(string &cuv,int poz,node *crt){
    if(crt==nullptr|| crt->cnt==0){
        return -1; 
    }
    if(poz==cuv.size()){
        return 0;
    }
    return 1+countPrefix(cuv,poz+1,crt->lit[cuv[poz]-'a']);
}
int main(){
    int cer;
    string s;
    node *root=new node();
    root->cnt=-1;
    while(fin>>cer>>s){

        if(cer==0){
            addWord(s,0,root);

        }else if(cer==1){
            bool erased=false;
            eraseWord(s,0,root,erased);
        }else if(cer==2){

            fout<<countWord(s,0,root)<<"\n";
        }else if(cer==3){

            fout<<countPrefix(s,0,root)<<"\n";
        }

    }
    return 0;
}